Simple bookmarklet to convert selected text to HTML entities

entity.js

function n(f) {
    return f.replace(/</g,"&lt;").replace(/>/g,"&gt;");
}
a = document.activeElement;
v = a.value;
s = a.selectionStart;
e = a.selectionEnd;
a.value = v.substr(0,s) + n(v.substr(s,e)) + v.substr(e,v.length);

/*

Bookmarklet code:

javascript:(function(){function%20n(f){return%20f.replace(/%3C/g,%22%26lt;%22).replace(/%3E/g,%22%26gt;%22);}a=document.activeElement;v=a.value;s=a.selectionStart;e=a.selectionEnd;a.value=v.substr(0,s)+n(v.substr(s,e))+v.substr(e,v.length);})();

/*